Watertight watch case

ABSTRACT

A watertight watch case wherein a glass is fixed to a bezel by interposing an L-shaped plastic ring in interference manner in a space formed by the glass and bezel, and wherein the bezel is fixed to a case body by interposing a plastic ring in interference manner in a space formed by a peripheral projection extending downwardly from the bezel and case body. This construction of the watch case provides excellent waterproof qualities even after the watch case is subjected to several assembling or disassembling operations.

United States Patent [1 1 Isono Feb. 5, 1974 WATERTIGHT WATCH CASE 75 I v t I S T k J Primary Examiner-George H. Miller, Jr. 1 n en or y 0 yo apan Attorney, Agent, or Firm-Eric H. Waters et al. [73] Assignee: Kabushiki Kaisha Daini Seikosha,

k Japan 57 ABSTRACT [22] Filed: 1972 A watertight watch case wherein a glass is fixed to a [21] App]. No.: 308,046 bezel by interposing an L-shaped plastic ring in interference manner in a space formed by the glass and be- U S Cl I 58/90 R zel, and wherein the bezel is fixed to a case body by [51] In.t .Cl .s. 37/08 interposing a plastic ring in interference manner in a [58] F.1d 58/90 R 91 space formed by a peripheral projection extending o ear downwardly from the bezel and case body. This con- [56] Refe ences Cit d struction of the watch case provides excellent waterr e proof qualities even after the watch case is subjected UNITED STATES PATENTS to several assembling or disassembling operations. 3,696,608 10/1972 Miyashita 58/91 X 2,467,062 4/1949 Vcrmo! 4. 58/90 R 9 Clalms, 1 Drawing Figure WATERTIGHT WATCH CASE FIELD OF THE INVENTION The present invention relates to watertight watch cases, and more particularly to watertight watch cases including relatively thin bezels.

BACKGROUND OF THE INVENTION conventionally, a watch glass or the like is closely fixed to an associated bezel with the two parts fitting each other in a so called interference manner (i.e., in such a manner as to impede the flow of liquid into the mechanism) or by the use of an adhesive agent. However, a glass, when fitted to a bezel in interference manner, suffers the disadvantage that the fixing capability thereof is gradually degraded due to wear resulting from several assembling or disassembling operations. This degradation and wear results in the disconnection of the glass from the bezel whereby no assurance of waterproof qualities can be possible. On the other hand, the use of an adhesive agent disadvantageously results in poor waterproof qualities because water can penetrate through cracks which usually form in the adhesive agent due to the distortion of the bezel when it is assembled or disassembled with respect to the glass.

SUMMARY OF THE INVENTION An object of the invention is to provide an improved watertight watch case which avoids the abovementioned disadvantages.

Another object of the present invention is to provide an improved watertight watch case having excellent waterproof qualities even after the watch case is subjected to several assembling or disassembling operations.

A still further object of the invention is to provide a watch case assembly which enables a fine view to be obtained because it allows making the bezel thinner.

To achieve the above and other objects of the present invention, there is provided a watertight watch case which comprises a one-piece case body, a bezel having a projection extending downwardly therefrom and having a shoulder portion provided thereon, a first ring mounted on the periphery of said case body, said bezel being, in watertight relation, fixed to said case body such that said projection is fitted to said first ring in an interference manner, there being a second ring mounted on said shoulder portion, and a glass fixed in watertight relation to said bezel such that said glass is fitted to said second ring in an interference manner.

This construction, which is provided in accordance with the present invention, has the following advantages:

l. The fitted portions of the glass and the bezel, and

the bezel and the case band are protected from wear as a result of assembling or disassembling operations, because plastic rings are used between the glass and the bezel and between the bezel and the case band.

2. The waterproof character of the case can be assuredly and easily reproduced by exchanging or replacing the above-mentioned rings.

3. The glass is prevented from cracking because the plastic ring absorbs any vertical or horizontal forces exerted on the glass.

4. The appearance of the watch case can be improved because the width of the bezel can be made thinner.

BRIEF DESCRIPTION OF THE DRAWING The invention will next be explained in greater detail in connection with the accompanying Drawing in which the sole figure is a cross-sectional view of a half of a watch case provided in accordance with the invention and taken alonga radial plane thereof.

DETAILED DESCRIPTION In the drawing is shown a preferred embodiment of the invention. More particularly, there is shown a wa tertight watch case which includes a case body 4 made of a single metallic piece serving as a case band and a back case.

Mounted on the inner wall of the case body 4 is a case ring 6 of L-shaped cross-section for supporting the watch movement. A plastic ring 5 serving to seal the watch against water is mounted on the inner peripheral wall of the case body. To aid in the sealing, ring 5 has a downwardly extending lip 5a whichis accommodated in a corresponding shoulder 4a formed internally on body 4. The ring 5 abuts against the top of case ring 6 and against shoulder 4a.

A bezel 2 has a stepped portion or shoulder 2b for receiving a glass 1. The outer diameter of the glass is slightly smaller than the inner diameter of the bezel to enable receiving an L-shaped plastic ring 3 in a space formed therebetween. For this purpose, the shoulder opens upwardly and inwardly.

Further, the bezel 2 has a projection 2a extending downwardly from the center of the bottom of the bezel. The outer diameter of the projection 2a is smaller than the corresponding inner diameter of the case body 4. This provides a space to receive the plastic ring 5 which is inserted in an interference manner as described below.

The inner diameters of the plastic rings 3 and 5 are made slightly smaller than the outer diameters of the glass 1 and the projection 2a, respectively, in order to assure waterproof qualities when the rings are inserted into the spaces between the glass 1 and bezel 2 and between the projection 2a and the case body 4, respectively.

It will be noted that the bezel is spaced in entirety from the glass by space 7 and from the case body and ring by space 8. It will also be seen that the inner edge 9 of projection 2a is bevelled as in the upper inner edge 10 of the case body 4.

Further to be noted is the downwardly and outwardly opening shoulder 11 oln the bezel which defines an annular space 12 with edge 10.

Finally, it will be noted that ring 3 and bezel 2 have co-planar tops 13 and 13' into which merges bevelled edge 14 of glass 1.

The glass 1 and the bezel 2 are fixed to the case body 4 as follows:

The glass 1 is force-fitted to the L-shapedring 3 in an interference manner and is then pressed or force fit against the stepped portion 2b of the bezel 2 together with the ring 3. Thereby the glass 1 is fixed to the bezel 2 and, consequently, is supported on the bezel 2 due to the pressure of the L-shaped ring 3. It is to be noted that the L-shaped ring 3 serves as a watertight material at the periphery of the glass. Similarly, the bezel 2 together with the glass 1 is fixed to the case body 4 by interposing or force-fitting plastic ring in an interference manner in the space formed by the case body 4 and the projection 2a. It will be understood that the ring 5 serves as the watertight material at the periphery of the bezel 4. Thus, the glass 1 is watertightly fixed to the bezel 2 through the plastic ring 3, and the bezel 2 is fixed to the case body 4 through the plastic ring 5. Lip 5a aids in the sealing and helps keep ring 6 in position.

In the above, the plastics for rings 3 and 5 may be, for example, Teflon, polycarbonate, Delrin or Duracon. The rings 3 and 5 may also be, for example, about mm. in outer diameter and about 18 mm. in inner diameter, respectively. Preferably, rings 3 and 5 will have a resilience or elastic coefficient of about 10 kg/cm at room temperature. Bezel 2 may be made of stainless steel or nickel silver, ring 6 of brass, and body 4 of stainless steel or brass, for example.

What is claimed is:

l. A watertight watch case comprising a one-piece case body, a bezel having a projection extending downwardly therefrom and having a shoulder portion opening upwardly and inwardly thereon, a first ring mounted on the periphery of said case body, said bezel being watertightly fixed to said case body in such a manner that said projection is fitted into said first ring in an interference manner, a second ring mounted on said shoulder portion, and a glass watertightly fixed to said bezel in such a manner that said glass is fitted to said second ring in an interference manner, said second ring being of L-shaped cross-section and engaging said glass along two angularly related surfaces thereof.

2. A watertight case according to claim 1, wherein said first and second rings are of plastic materials.

3. A watertight case according to claim 2 wherein said case body includes a shoulder, comprising a case ring in said body adjacent said shoulder, said first ring including a downwardly extending lip accommodated by the latter said shoulder between the case ring and case body.

4. A watertight case according to claim 3, wherein the bezel is spaced in entirety from said glass and said case body and ring.

5. A watertight case according to claim 4, wherein the first ring has a force fit on said glass and the second ring has a force fit on said projection.

6. A watertight case according to claim 5 wherein the case body has a bevelled upper inner edge.

7. A watertight case according to claim 6 wherein the projection extends downwardly from the center of the bottom of the bezel.

8. A watertight case according to claim 7 wherein the bezel includes a downwardly and outwardly opening shoulder which defines a space with the bevelled upper inner edge of the case body.

9. A watertight case according to claim 8 wherein the bezel and second ring have flush tops and the glass has a bevelled edge merging into said tops. 

1. A watertight watch case comprising a one-piece case body, a bezel having a projection extending downwardly therefrom and having a shoulder portion opening upwardly and inwardly thereon, a first ring mounted on the periphery of said case body, said bezel being watertightly fixed to said case body in such a manner that said projection is fitted into said first ring in an interference manner, a second ring mounted on said shoulder portion, and a glass watertightly fixed to said bezel in such a manner that said glass is fitted to said second ring in an interference manner, said second ring being of L-shaped crosssection and engaging said glass along two angularly related surfaces thereof.
 2. A watertight case according to claim 1, wherein said first and second rings are of plastic materials.
 3. A watertight case according to claim 2 wherein said case body includes a shoulder, comprising a case ring in said body adjacent said shoulder, said first ring including a downwardly extending lip accommodated by the latter said shoulder between the case ring and case body.
 4. A watertight case according to claim 3, wherein the bezel is spaced in entirety from said glass and said case body and ring.
 5. A watertight case according to claim 4, wherein the first ring has a force fit on said glass and the second ring has a force fit on said projection.
 6. A watertight case according to claim 5 wherein the case body has a bevelled upper inner edge.
 7. A watertight case according to claim 6 wherein the projection extends downwardly from the center of the bottom of the bezel.
 8. A watertight case according to claim 7 wherein the bezel includes a downwardly and outwardly opening shoulder which defines a space with the bevelled upper inner edge of the case body.
 9. A watertight case according to claim 8 wherein the bezel and second ring have flush tops and the glass has a bevelled edge merging into said tops. 